package net.carinae.dev.seduku.utils;

import java.util.Set;
import com.google.common.collect.SetMultimap;

// The needed operations for a square index

public interface SquareIndex {

    Set<? extends SquareIndex> unit(SudokuUnits unit);
    
    SetMultimap<SudokuUnits, ? extends SquareIndex> units();
    
    Set<? extends SquareIndex> peers();
    
}
